Rewrite ${((5^{10})(8^{5}))^{-3}}$ in the form ${5^n \times 8^m}$.
${ ((5^{10})(8^{5}))^{-3} = (5^{(10)(-3)})(8^{(5)(-3)})} $ ${\hphantom{ ((5^{10})(8^{5}))^{-3}} = 5^{-30} \times 8^{-15}} $